The overall research objective is to describe and explain the development, maintenance, and decline of children's behavior problems during middle childhood, and then to examine their implications for adolescent behavior. The investigators focus on two major categories of problems--externalizing behavior that is troubling to others, especially aggressive and antisocial behavior, and internalizing behavior marked by withdrawal from interaction and depressed mood. There are two specific aims: 1) to describe and explain the trajectory of behavior problems during a four- year period spanning ages 6 to 11. To accomplish this, they will first develop models explaining the levels of children's behavior problems at the beginning of middle childhood (ages six and seven), then test analytic models predicting changes from that point to ages 10 to 11 four years later; and 2) to follow a subset of children forward into adolescence to evaluate how the developmental trajectory established during middle childhood is linked to normative and non-normative behaviors in adolescence. To accomplish these aims, the investigators will use the Child-Mother data sets of the National Longitudinal Surveys of Youth; they will draw on data from five waves of child assessment (1986, 1988, 1990, 1992, and 1994) for a large national sample of children born to a nationally representative sample of U.S. women to develop a sample of approximately 2,400 children who are followed through the middle childhood period. They will evaluate three sets of influences on the development and persistence of behavior problems during middle childhood: 1) parental characteristics; 2) chronic social stressors impinging on the family; and 3) the quality of the home environment that parents provide. Analyses consider the causal linkages among these explanatory variables, tracing both direct and indirect effects.Second, they explicitly control for (and evaluate the direct and indirect effects of) prior parental resources that predispose parents to differing stress levels over time. Finally, they evaluate theoretically expectable interactions among these explanatory sets, as well as by race-ethnicity and child gender, in which the effects of any single circumstance or resource are contingent on levels of other variables. These results will contribute to social- scientific theories regarding the life-course development of social competence and mental health, and suggest strategies for interventions with children who are otherwise likely to reach adulthood without the requisite emotional and social competencies.